HOW TO KNOW THE FRESH-WATER ALGAE 



317a Cells contained in a gelatinous envelope. Fig. 222 



CHLOROBOTRYS 



Fig. 222. Chlorobotrys iegulaiis (West) 

 Bohlin. a, single cell; b, two cells 

 inclosed in common mucilage. 



The identifying character of this spe- 

 cies is the paired arrangement of the 

 spherical cells inclosed in a mucilagin- 

 ous sheath. There are several parietal 

 chromatophores and a red spot which 

 is an oil globule. Even though pre- 

 served, when some identifying char- 

 acteristics are lost, the cells retain the 

 dark-colored spot. 



Figure 222 



317b Cells not inclosed in a gelatinous envelope 



318 



318a Cell wall in 2 sections, separating and persisting as membran- 

 ous sections near the liberated autospores (small replicas of the 

 parent cell). Fig. 223 DIACHROS 



Fig. 223. Diachros simplex Pascher. 



This is the only species reported from 

 the United States. It is somewhat like 

 Schizochlamys (Fig. 48) in the Chlorophyta 

 in that the mother-cell wall fragments are 

 retained after new cells (autospores) are 

 released and these persist as hemispheri- 

 cal, transparent cups near the daughter 

 cells. 



Figure 223 



318b Cell wall in 1 piece; mother-cell not forming persisting sections 

 but degenerating to liberate spores 319 



136 



